title: Isolation and characterization of factor X activator from the venom of Vipera aspis aspis.
abstract: 1. A factor X activator was isolated from the venom of Vipera aspis aspis (Aspic viper) by gel filtration and ion-exchange chromatography. 2. The purified activator has a mol. wt of 75,000 and an isoelectric point of 4.6. Upon reduction, this activator migrated as two bands with mol. wts of 16,000 and 14,000 in sodium dodecyl sulfate polyacrylamide gel electrophoresis. 3. The activator from V. a. aspis venom shortened activated partial thromboplastin time (APTT) of normal plasma and factor IX-deficient plasma from humans. 4. Factor X incubated with isolated activator and calcium ions drastically shortened APTT of factor X-deficient plasma and expressed hydrolytic activity against synthetic substrates for factor Xa, however no hydrolytic activity was detected with the activator alone, indicating that the activator converted factor X to the active form.
authors.affiliation: Department of Microbiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Komori
authors.forename: T
authors.initials: T
authors.lastname: Nikai
authors.forename: H
authors.initials: H
authors.lastname: Sugihara
mesh_terms: D000595:Amino Acid Sequence; D001777:Blood Coagulation / Q000187:drug effects; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D005170:Factor X / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009363:Neoplasm Proteins; D010084:Oxidation-Reduction; D010314:Partial Thromboplastin Time; D014757:Viper Venoms / Q000032:analysis*
chemical_list: D009363:Neoplasm Proteins; D014757:Viper Venoms; D005170:Factor X; D003546:Cysteine Endopeptidases; C030910:cancer procoagulant